Radio frequency in treatment of AVNRT arrhythmia

AV-node modification by catheter RF energy delivery is treatment of choice in the symptomatic patients with AVNRT. This study included 30 patients with AVNRT (19 women, 11 men). We did slow pathway ablation in 29 cases successfully. Maximum effective energy delivery was 40 watts for 40 msec. 1:1 AV conduction increased from 290±40 msec before ablation to 340±65 msec after ablation. Also AV-node ERP increased from 235±35 msec before ablation to 280±65 msec after that. There was no recurrence of arrhythmia in the group with slow pathway ablation during 28 months follow-up. We did fast pathway ablation in one case. In this patient AH interval increased from 120 to 200 msec, maximum RF energy delivery was 20 watts for 20 msec (2 times). Recurrence of non sustained PSVT occurred in this patients 20 months after RF ablation. There was no case of permanent AV Block. We recommond slow pathway catheter RF ablation in patients with symptomatic AVNRT

Prosthetic Tricuspid Valve Thrombosis: Three Case Reports and Literature Review

A common complication of prosthetic heart valves is thrombosis. Although the incidence of prosthetic valve thrombosis (PVT) in the tricuspid position is high, there are not enough data on the management of it, in contrast to left-sided PVT. Here, we describe three cases of tricuspid PVT with three different management approaches: thrombolytic therapy; close observation with oral anticoagulants; and surgery. The first case was a woman who suffered from recurrent PVT, for which we successfully used Tenecteplase for second and third episodes. We employed Tenecteplase in this case for the first time in the therapy of tricuspid PVT. The second case had fixed leaflets in open position while being symptomless. At six months' follow-up, with the patient having taken oral anticoagulants, the motion of the leaflets was restricted and she was symptom- free. The last case was a woman who had a large thrombus in the right atrium immediately after mitral and tricuspid valvular replacement. The patient underwent re-replacement surgery and a new biological valve was implanted in the tricuspid position. Also, we review the literature on the pathology, signs and symptoms, diagnosis, and management of tricuspid PVT

Atrial Standstill: A Rare Case

We introduce a 32-year-old man who was evaluated for a dizziness and headache of unknown origin for at least two months and was referred to our center after ECG findings. He was finally diagnosed as a case of idiopathic, familial, diffuse, persistent atrial standstill, which is a rare arrhythmogenic condition characterized by the absence of electrical and mechanical activity in the atria. He successfully received a single-chamber permanent pacemaker

Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia: Success Rates and Complications during 14 Years of Experience

Background: Radiofrequency catheter ablation (RFCA) has been introduced as the treatment of choice for supraventricular tachycardia. The aim of this study was to evaluate the success rate as well as procedural and in-hospital complications of RFCA for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT).Methods: Between March 1995 and February 2009, 544 patients (75.9% female, age: 48.89 ± 13.19 years) underwent 548 RFCAs for AVNRT in two large university hospitals. Echocardiography was performed for all the patients before and after the procedure. Electrocardiograms were recorded on digital multichannel systems (EP-Med) or Bard EP system. Anticoagulation was initiated during the procedure.Results: From the 548 patients, 36 had associated arrhythmias, atrial flutter (4%), atrial fibrillation (0.7%), concurrent atrial fibrillation and atrial flutter (0.7%), and concealed atrioventricular pathway (0.4%). The overall success rate was 99.6%. There were 21 (3.9%) transient III-degree AV blocks (up to a few seconds) and 4 (0.7%) prolonged II- or III-degree AV blocks, 2 (0.25%) of which required permanent pacemaker insertion, 3(0.5%) deep vein thrombosis, and one (0.2%) arteriovenous fistula following the procedure. No difference was observed in the echocardiography parameters before and after the ablation.Conclusion: RFCA had a high success rate. The complication rate was generally low and in the above-mentioned centers it was similar to those in other large centers worldwide. Echocardiography showed no difference before and after the ablation. The results from this study showed that the risk of permanent II or III-degree AV block in patients undergoing RFCA was low and deep vein thrombosis was the second important complication. There was no risk of life-threatening complications

Comparison of Benefits from Cardiac Resynchronization Therapy between Patients with Ischemic Cardiomyopathy and Patients with Idiopathic Dilated Cardiomyopathy

Background: Cardiac resynchronization therapy (CRT) is an effective treatment for patients with moderate to severe heart failure. However, 20-30% of patients remain non-responders to CRT. We sought to identify which patients benefit the most from CRT in regard to the etiology of heart failure. Methods: Eighty-three consecutive patients (62 men) who had a biventricular pacemaker inserted at Tehran Heart Center between May 2004 and March 2007 were evaluated retrospectively. The inclusion criteria were comprised of New York Heart Association (NYHA) class III or IV, left ventricular ejection fraction<35%, and QRS>120ms. After 6 months, response was defined as being alive, no hospitalization for cardiac decompensation, and an improvement in NYHA class>1 grade. Results: After 6 months, 60 patients out of the 83 patients were responders. Amongst the 83 patients, 48 had ischemic cardiomyopathy and 35 had non-ischemic cardiomyopathy. A cross-tabulation of response versus etiology showed no significant difference between ischemic versus non-ischemic cardiomyopathy with regard to response to CRT (P=0.322). Conclusion: According to our study, there was no difference in response to CRT between ischemic versus non-ischemic cardiomyopathy at six months’ follow-up

Anatomy of Atrioventricular Node Artery and Pattern of Dominancy in Normal Coronary Subjects: A Comparison between Individuals with and without Isolated Right Bundle Branch Block

Background: Isolated right bundle branch block (RBBB) is a common finding in the general population. The atrioventricular node (AVN) artery contributes to the blood supply of the right bundle branch. Our hypothesis was that the anatomy of the AVN artery and the pattern of dominancy differ between subjects with and without RBBB. Methods: We retrospectively studied the coronary angiography of 92 patients with RBBB and 184 age- and gender- matched controls without RBBB. All the subjects had angiographically proven normal coronary arteries. The dominant circulation and precise origin of the AVN artery were determined in each subject. Obtained data were compared between the two study groups. Results: There was no significant difference between the two groups in terms of dominancy (p value = 0.200). Origination of the AVN artery from the right circulatory system was more common in both groups, but this pattern was more prevalent in the cases than in the controls (p value = 0.021). There was a great variation of the AVN artery origin. In the total study population, the AVN artery was more commonly separated from a non crux origin than from the crux area. The prevalence of the non-crux origination of the AVN artery was significantly higher in the cases than in the controls (p value < 0.001). While the origination of the AVN artery from the right circulatory system was more common in both groups, the prevalence of the right origin of the AVN artery was significantly higher in the cases than in the controls. We observed that the AVN artery most commonly originated from the dominant artery but not necessarily from the crux. Conclusion: The anatomy of the AVN artery but not the pattern of dominancy is somewhat different in subjects with RBBBcompared with normal individuals

Age and the head-up tilt test outcome in syncope patients

Background: The head-up tilt test (HUTT) is a useful diagnostic tool for syncope. Objectives: We sought to investigate the outcome of the HUTT in syncope patients and identify the relationship between age and different hemodynamic outcomes. Patients and Methods: In this cross-sectional study, we prospectively enrolled consecutive patients who presented with syncope and underwent the HUTT with a clinical suspicion of neurocardiogenic syncope after the exclusion of orthostatic hypotension cases. The HUTT consisted of consecutive passive and active phases. In the passive phase, the patients were tilted at 70 degrees for 20 minutes; and if negative, the test was repeated with 400 micrograms of sublingual nitroglycerin for another 20 minutes. Positive responses were classified according to the classification of the vasovagal syncope international study (VASIS) and compared for age and gender. Results: A total of 498 patients were enrolled (age = 44.93 ± 18.77 years; male = 271 [54.4%]). Overall, 291 (58.4%) patients had a positive HUTT, while 256 (88.5%) patients had a positive result during the active phase. The test results were as follows: 107 (36.7%) mixed type (VASIS I), 103 (35.3%) cardioinhibitory (VASIS IIA = 44 [15.1%]; VASIS IIB = 59 [20.2%]), and 80 (27.4%) vasodepressive (VASIS III). There was no relationship between gender and syncope type. The trend of the HUTT result significantly changed with age, and the rate of cardioinhibitory syncope decreased after middle ages (P value for trend = 0.02). Conclusions: Hemodynamic response to the HUTT was associated with age. Cardioinhibitory response became less frequent with age due to exaggerated vagal activity in the younger patients as compared with the older subjects

Characterization of Suitability of Coronary Venous Anatomy for Targeting Left Ventricular Lead Placement in Patients Undergoing Cardiac Resynchronization Therapy

Background: Differences in the quantity and distribution of coronary veins between patients with ischemic and non-ischemic cardiomyopathy might affect the potential for the left ventricular (LV) lead targeting in patients undergoing cardiac resynchronization therapy (CRT). In the current study, we assessed and compared the suitability of the coronary venous system for the LV lead placement in ischemic and dilated cardiomyopathy. Methods: This single-centre study, performed at our hospital, retrospectively studied 173 patients with the New York Heart Association class III or IV who underwent CRT. The study population was comprised of 74 patients with an ischemic underlying etiology and 99 patients with a non-ischemic etiology. The distribution of the veins as well as the final lead positions was recorded. Results: There was no significant difference between the two groups in terms of the position of the available suitable vein with the exception of the posterior position, where the ischemic group had slightly more suitable veins than did the dilated group (48.4% versus 32.1%, p value = 0.049). There was also no significant difference with respect to the final vein, through which the LV lead was inserted. Comparative analysis showed that the patients with previous coronary artery bypass grafting surgery (CABG) had significantly fewer suitable veins in the posterolateral position than did the non-CABG group (16.3% versus 38.7%, p value = 0.029). There was, however, no significant difference between the two subgroups regarding the final vein position in which the leads were inserted. Conclusion: The final coronary vein position suitable and selected for the LV lead insertion was not different between the cases with cardiomyopathy with different etiologies, and nor was it different between the ischemic cases with and without a history of CABG. Patients with a history of procedures around the coronary vessel may have an intact or recovered venous system and may, therefore, benefit from transvenous LV lead placement for CRT